Immunotherapy‐responsive brainstem lesion accompanied with anti‐galactocerebroside antibody

Abstract

AbstractBackgroundBrainstem lesions are a diagnostic challenge and clinicians have to differentiate between many diseases including acute disseminated encephalomyelitis, multiple sclerosis (MS), Bickerstaff brainstem encephalitis (BBE) and brain tumors. The anti‐galactocerebroside (Gal‐C) antibody is an anti‐glycolipid antibody that is often detected in autoimmune peripheral neuropathy. However, anti‐Gal‐C antibody is rarely detected in autoimmune central nervous system diseases. Here, we report the case of an anti‐Gal‐C antibody‐positive patient who had a brainstem lesion that mimicked MS and responded to immunotherapy.Case presentationWe report a 32‐year‐old woman who presented with subacute numbness of the right lower extremities and hemiataxia. Her cerebrospinal fluid examination showed an elevated myelin basic protein level and an oligoclonal band. Brain magnetic resonance imaging showed a T2 high‐intensity lesion from the left brainstem to the cerebellum. She was treated with steroid pulse therapy, but internuclear ophthalmoplegia and left peripheral facial palsy developed. Her brain magnetic resonance imaging showed an enlargement of the brainstem lesion. Therefore, plasma exchange therapy and high‐dose immunoglobulin therapy were administered, and her symptoms eventually ameliorated. First, we diagnosed her with MS and started dimethyl fumarate. After anti‐GM2 and anti‐Gal‐C antibody positivity was revealed, we diagnosed an anti‐Gal‐C antibody‐related brainstem lesion. There have been few reports of anti‐Gal‐C antibody‐positive central nervous system diseases.ConclusionsThe present case highlights that an anti‐Gal‐C positivity can cause brainstem inflammatory lesions, which should be differentiated from acute disseminated encephalomyelitis, Bickerstaff brainstem encephalitis and MS. The patient’s symptoms improved with intense immunotherapy, and antibody measurement led to the discontinuation of unnecessary disease‐modifying drugs.